Fossil species that can be conclusively identified as stem-relatives of stick- and leaf-insects (Phasmatodea) are extremely rare, especially for the Mesozoic era. This dearth in the paleontological record makes assessments on the origin and age of the group problematic and impedes investigations of evolutionary key aspects, such as wing development, sexual size dimorphism and plant mimicry.

Methodology/Principal Findings

A new fossil insect species, Cretophasmomima melanogramma Wang, Béthoux and Ren sp. nov., is described on the basis of one female and two male specimens recovered from the Yixian Formation (Early Cretaceous, ca. 126±4 mya; Inner Mongolia, NE China; known as ‘Jehol biota’). The occurrence of a female abdominal operculum and of a characteristic ‘shoulder pad’ in the forewing allows for the interpretation of a true stem-Phasmatodea. In contrast to the situation in extant forms, sexual size dimorphism is only weakly female-biased in this species. The peculiar wing coloration, viz. dark longitudinal veins, suggests that the leaf-shaped plant organ from the contemporaneous ‘gymnosperm’ Membranifolia admirabilis was used as model for crypsis.

Conclusions/Significance

As early as in the Early Cretaceous, some stem-Phasmatodea achieved effective leaf mimicry, although additional refinements characteristic of recent forms, such as curved fore femora, were still lacking. The diversification of small-sized arboreal insectivore birds and mammals might have triggered the acquisition of such primary defenses.

Etymology: Specific epithet composed of ‘melano’, Ancient Greek for ‘black’, and ‘gramme’, Ancient Greek for ‘line’; referring to the coloration of forewings, and of hind wing apices.

Conclusion:

Based on the combination of observed characters, viz. presence of ‘shoulder pads’ in the forewings, aspect ratios of thoracic segments and legs, unsegmented cerci, we infer that Cretophasmomima melanogramma is a genuine stem-Phasmatodea. The fossil stick insect already possessed leaf (or leaf-shaped organ) mimicking capabilities, but retained a number of putative plesiomorphic traits in regard to extant forms, such as presence of mandibular incisivi, two lacinial teeth, straight fore femora, well-developed long forewings in both sexes and a low degree of sexual size dimorphism that is only moderately female-biased. This new record suggests that leaf mimicry predated the appearance of twig and bark mimicry in phasmatodeans. Additionally, it complements our growing knowledge of the early attempts of insects to mimic plant parts

The oviraptorosaurian theropod dinosaur clade Caenagnathidae has long been enigmatic due to the incomplete nature of nearly all described fossils. Here we describe Anzu wyliei gen. et sp. nov., a new taxon of large-bodied caenagnathid based primarily on three well-preserved partial skeletons. The specimens were recovered from the uppermost Cretaceous (upper Maastrichtian) Hell Creek Formation of North and South Dakota, and are therefore among the stratigraphically youngest known oviraptorosaurian remains. Collectively, the fossils include elements from most regions of the skeleton, providing a wealth of information on the osteology and evolutionary relationships of Caenagnathidae. Phylogenetic analysis reaffirms caenagnathid monophyly, and indicates that Anzu is most closely related to Caenagnathus collinsi, a taxon that is definitively known only from a mandible from the Campanian Dinosaur Park Formation of Alberta. The problematic oviraptorosaurs Microvenator and Gigantoraptor are recovered as basal caenagnathids, as has previously been suggested. Anzu and other caenagnathids may have favored well-watered floodplain settings over channel margins, and were probably ecological generalists that fed upon vegetation, small animals, and perhaps eggs.

Anzu wyliei skull, shown in a reconstruction, featured a bony crest

Systematic paleontology

Theropoda Marsh 1881

Oviraptorosauria Barsbold 1976

Caenagnathidae Sternberg 1940

Anzu gen. nov.

Anzu wyliei sp. nov.

Etymology: The genus name is for Anzu, a feathered demon in ancient Mesopotamian (Sumerian and Akkadian) mythology, and alludes to the distinctive appearance of this large, presumably feathered dinosaur. The species name is for Mr. Wylie J. Tuttle, grandson of Mr. and Mrs. Lee B. Foster, in recognition of Mr. and Mrs. Foster's generous support of the scientific research and collections activities at Carnegie Museum of Natural History.

Tuesday, March 18, 2014

Cycas sancti-lasallei, a new species from Mindanao Island, the Philippines is described and illustrated. It can be distinguished from other Cycas species in the Philippines in having long leaves, undulating leaflets, and megasporophyll lamina with a semi-orbicular to orbicular base and triangular top with few but well-defined spines. A key to the species of Cycas currently described from the Philippines is provided.

Chin Cheung Tang, Bine Xue, Richard M.K. Saunders. 2013. A new species of Goniothalamus (Annonaceae) from Palawan, and a new nomenclatural combination in the genus from Fiji. PhytoKeys. 32: 27–35, doi: dx.doi.org/10.3897/phytokeys.32.6663

We present herein data on morphology and distribution of the cave knifefish Eigenmannia vicentespelaea Triques, 1996, from the São Domingos karst area, Central Brazil, comparing it to the epigean (surface) species, Eigenmannia sp., found in the same area (but not syntopic with E. vicentespelaea) and also with congeners from other localities. Collecting sites comprising epigean and subterranean stream reaches in São Domingos were sampled during the dry seasons of 1999, 2000, and 2001 using several methods. Preserved specimens of E. vicentespelaea (n=25, including holotype and paratype) and of Eigenmannia sp. (n=15) were compared with focus on morphometric characters, body pigmentation and eye condition. A combination of characters separates E. vicentespelaea from Eigenmannia sp. and other congeners: the length from the tip of the snout to the posterior of the anal fin base, ocular diameter: head length and pre-anal distance: head length proportions, and body pigmentation. A wider morphometric variation in E. vicentespelaea is described than that reported in the original description (based on two specimens).

One of the most remarkable examples of convergent evolution among vertebrates is illustrated by the independent origins of an active electric sense in South American and African weakly electric fishes, the Gymnotiformes and Mormyroidea, respectively. These groups independently evolved similar complex systems for object localization and communication via the generation and reception of weak electric fields. While good estimates of divergence times are critical to understanding the temporal context for the evolution and diversification of these two groups, their respective ages have been difficult to estimate due to the absence of an informative fossil record, use of strict molecular clock models in previous studies, and/or incomplete taxonomic sampling. Here, we examine the timing of the origins of the Gymnotiformes and the Mormyroidea using complete mitogenome sequences and a parametric Bayesian method for divergence time reconstruction. Under two different fossil-based calibration methods, we estimated similar ages for the independent origins of the Mormyroidea and Gymnotiformes. Our absolute estimates for the origins of these groups either slightly postdate, or just predate, the final separation of Africa and South America by continental drift. The most recent common ancestor of the Mormyroidea and Gymnotiformes was found to be a non-electrogenic basal teleost living more than 85 millions years earlier. For both electric fish lineages, we also estimated similar intervals (16–19 or 22–26 million years, depending on calibration method) between the appearance of electroreception and the origin of myogenic electric organs, providing rough upper estimates for the time periods during which these complex electric organs evolved de novo from skeletal muscle precursors. The fact that the Gymnotiformes and Mormyroidea are of similar age enhances the comparative value of the weakly electric fish system for investigating pathways to evolutionary novelty, as well as the influences of key innovations in communication on the process of species radiation.

Lepidocephalus has been assumed to include only two species and confined to peninsular Malaysia and Indonesia. However, based on records and collections reported herein, the genus contains five species and is most common in the Chao Phraya basin of Thailand. Large rivers seem to be the preferred habitat, and difficulty in collecting these rivers may account for the paucity of specimens in collections. The known range of these five species includes western and southern Borneo, Java, Sumatra, peninsular Malaysia, and central Thailand.

Etymology. The name nanensis, an adjective, refers to the river system where most specimens have been collected.

Distribution. Lepidocephalus nanensis is found in Thailand in the Nan River and in the Chao-Phraya River below the confluence of the Nan and Yom rivers (Fig. 2). To our knowledge, Šlechtová et al. (2008) first recorded this species from Thailand (as L. macrochir) and included molecular data from specimens collected at a fishpond at Nakom Savan (Nakon Sawan, Nakon Sawan Province), Thailand. Recent collections suggest that this species is common in the Nan and lower Chao Phraya rivers. These large rivers seem to be the preferred habitat of the species.

Microcobitis, new genus, is established with Cobitis misgurnoides Rendahl, 1944 as type species. It is diagnosed by having the lower lip developed into four barbel-like lobes, adult males bearing a lamina circularis at the base of the second pectoral-fin ray, suborbital spine in a groove under the eye and not covered by skin, a pre-epiphysal fontanel between the frontal bones, a cartilaginous epiphysal bar, and the absence of body swellings in males.

Etymology. The name is derived from the Greek word ‘micros’, small, used as prefix here, and the generic name Cobitis, the type genus of Cobitidae, in which Microcobitis was originally placed due to the similar shape of the lamina circularis in males. Gender feminine.

Distribution. Presently reported from river basins in Central Vietnam. Microcobitis has also been reported to occur in some tributaries of the Mekong in Laos on the western slope of the Annamite range (M. Kottelat, pers. comm.).

Sunday, March 16, 2014

Schistura crocotula, a new species, is described from Khanan River, Prachuap Khiri Khan Province, southern Thailand. It is distinguished from other species of Schistura in Southeast Asia by a depressed head; 6-11 dark brown bars against an orange background; the first bar is the widest, two bars are under dorsal fin; interspaces are often indistinct on posterior part of body; a thick black bar at the base of the caudal fin.

Diagnosis: Schistura crocotula is distinguished from the other species of the genus by the combination of the following characters: lateral line incomplete; 7 1/2 branched dorsal-fin rays; 8 + 8 branched caudal-fin rays; pelvic-fin origin in front of dorsal-fin origin; anterior nostril pierced on front side of a pointed flap reaching eye; body with 6-11 regular dark brown bars on an orange (in life) or gray (when preserved) background; the first bar is wider than other bars; one or two bars are under dorsal fin, 1-1.5 times wider than interspaces; bars and interspaces often indistinct posterior to anus and orange-brown in life; black basal caudal bar conspicuous, wide, reaching dorsal and ventral midlines.

Size: 48.5 mm SL

Distribution:Schistura crocotula is known only from the Khanan River in Bangsapan and Pranburi river in Pranburi, Prachuap Khiri Khan Province, peninsular Thailand. It is possible that some of the S. robertsi samples reported by Kottelat (1990) include more than one species and that some specimens from the eastern slope of peninsular Thailand (NIFI 2071) might be S. crocotula. The juvenile specimen from Tapi drainage (CMK 5179, 22.5 mm SL) also reported as S. robertsi is plain brown and uninformative; the identity of this population requires sampling of adult specimens.

Etymology: The species name crocotula is derived from the Latin name of a saffron garment (a saffron-coloured dress) and refers to the background colour of the live fish.

Schistura maculosa, a new species of loach, is described from Tuingo and Pharsih Rivers, tributaries of Tuivai River (Barak drainage) in Mizoram, northeastern India. It is distinguished from other closely related Schistura species in having an axillary pelvic lobe; an incomplete lateral line; 20–30 narrow black bars on the body; 3–4 rows of black spots horizontally across the dorsal-fin; a slightly emarginate caudal-fin, with 5–7 rows of black spots more or less regularly arranged vertically on rays across the fin, and 8+8 branched caudal-fin rays.

Four fish species are known from inside Phuong Hoang cave in northern Vietnam. Pterocryptis crenula and Schistura cf. fasciolata are hypogean populations of epigean species. Cyprinus rubrofuscus individuals do not show morphological adaptations to the cave environment. Schistura mobbsi, new species, is characterized by the loss of the eyes, pigmentation and lateral line, reduced number of fin rays, large nostrils displaced forward on snout, and scales not overlapping and restricted to posterior part of flank, becoming very sparsely set anteriorly

Recent fieldwork has revealed the presence of six species of Schistura McClelland 1838 in the Mae Khlong basin in southwestern Thailand. These include S. sexcauda(Fowler 1937), S. balteata (Rendahl 1948), S. mahnerti Kottelat 1990, the recently described S. aurantiacaPlongsesthee et al. 2011 and S. tenebrosa Kangrang et al. 2012, and a newly discovered species described herein. Schistura sexcauda previously was the only Schistura species known in the Mae Khlong, and it was mis-identified as S. desmotes(Fowler 1934). Schistura pantherina, n. sp., is easily distinguished from all other species of Schistura by its distinctive color pattern. It appears to be endemic to the Mae Nam Kwai Noi system.

A new species of Schistura is described from the Kwai Noi, Mae Khlong basin, in the Thong Pha Phum District of Kanchanaburi Province in western Thailand. The species is distinguished from all other species of Schistura by a uniform dusky brown color pattern without marks on the dorsum or side of body and with many conspicuous supplementary neuromasts along the lateral line and on the head. It is further distinguished from other species of Schistura lacking marks on the body by its dark brown color, an incomplete lateral line extending only to beneath the dorsal fin, and the origin of the dorsal fin located above the origin of the pelvic fin. The species is small, reaching only 46.0 mm SL, 55.1 mm TL, and inhabits shallow gravel and rubble riffles in small streams.

The lineage of apes and humans (Hominoidea) evolved and radiated across Afro-Arabia in the early Neogene during a time of global climatic changes and ongoing tectonic processes that formed the East African Rift. These changes probably created highly variable environments and introduced selective pressures influencing the diversification of early apes. However, interpreting the connection between environmental dynamics and adaptive evolution is hampered by difficulties in locating taxa within specific ecological contexts: time-averaged or reworked deposits may not faithfully represent individual palaeohabitats. Here we present multiproxy evidence from Early Miocene deposits on Rusinga Island, Kenya, which directly ties the early ape Proconsul to a widespread, dense, multistoried, closed-canopy tropical seasonal forest set in a warm and relatively wet, local climate. These results underscore the importance of forested environments in the evolution of early apes.

Modern porpoises (Odontoceti: Phocoenidae) are some of the smallest cetaceans and usually feed near the seafloor on small fish and cephalopods. Within both extinct and extant phocoenids, no evidence for specialized mandibular morphology has been documented. Here we describe a new species of extinct porpoise, Semirostrum ceruttii, from the marine Pliocene San Diego (4.2–1.6 mega-annum, Ma) and Purisima (5–2.5 Ma) formations of California. The mandibles comprise a long, fused, and nearly edentulous prognathous symphysis, extending farther beyond the rostrum than in any known mammal. Phylogenetic analyses based on morphology reconstruct Semirostrum ceruttii as sister to extant (crown) porpoise species with moderate support. We describe the spectacularly preserved holotype specimen based on computed tomography (CT) scans, which allowed visualization of the elongate mental and accessory canals within the symphysis. The elongate canals are similar to those found in Rynchops birds and were likely involved in sensory function. Oblique labial wear facets present on numerous small conical mandibular teeth posterior to the symphysis suggest regular contact with benthic substrate. The unique mandibular and dental characteristics, along with robust scapulae, sternum, and unfused cervical vertebrae, support the interpretation that this species employed a form of benthic skim feeding by using its mandible to probe for and obtain prey.

Marine mammal mass strandings have occurred for millions of years, but their origins defy singular explanations. Beyond human causes, mass strandings have been attributed to herding behaviour, large-scale oceanographic fronts and harmful algal blooms (HABs). Because algal toxins cause organ failure in marine mammals, HABs are the most common mass stranding agent with broad geographical and widespread taxonomic impact. Toxin-mediated mortalities in marine food webs have the potential to occur over geological timescales, but direct evidence for their antiquity has been lacking. Here, we describe an unusually dense accumulation of fossil marine vertebrates from Cerro Ballena, a Late Miocene locality in Atacama Region of Chile, preserving over 40 skeletons of rorqual whales, sperm whales, seals, aquatic sloths, walrus-whales and predatory bony fish. Marine mammal skeletons are distributed in four discrete horizons at the site, representing a recurring accumulation mechanism. Taphonomic analysis points to strong spatial focusing with a rapid death mechanism at sea, before being buried on a barrier-protected supratidal flat. In modern settings, HABs are the only known natural cause for such repeated, multispecies accumulations. This proposed agent suggests that upwelling zones elsewhere in the world should preserve fossil marine vertebrate accumulations in similar modes and densities.